【摘要】 为促进直喷式汽油机冷启动工况下缸内均匀混合气的形成,提出一种应用于直喷式汽油机的新式供油系统——复合供油系统.采用三维数值模拟方法,探讨其低压供油部分喷油器位置的优化设计,分析复合供油系统对直喷式汽油机冷启动工况下缸内油气混合状态的影响.结果表明,选择适当的低压喷油器位置对进气歧管内油气混合过程以及进气冲程中进入缸内的混合气浓度影响很大,复合供油系统能够改善冷启动工况下缸内空燃比分布,促进缸内油气充分混合,降低HC排放.更多还原

【Abstract】 To improve the mixing of homogenous air-fuel in cylinder,a new fuel supply system for gasoline direct injection engine,compound fuel supply system was presented. With the three-dimensional numerical simulation method,the optimum design of low-pressure fuel injector position was investigated,and the influence of compound fuel supply system on the air-fuel mixture formation in cylinder under the cold-start condition of GDI engine was analyzed. The results showed that the air-fuel mixing process in intake manifolds and the concentration of mixture entered into the cylinder during the intake stroke were greatly influenced by the low-pressure fuel injector position. The compound fuel supply system can improve the mixing of air-fuel and the distribution of air-fuel ratio in cylinder under the cold-start condition,and reduce the HC emission.更多还原